In high school, Brandon Lilly weighed 170 pounds. Last week he topped out at 322.

Lilly, 29, is a professional powerlifter who trains at private Grove City gym Lexen Xtreme. He is in the business of pushing his body to the limit and beyond, constantly stretching his threshold for size and strength. Some powerlifters can keep upping their lifts while maintaining a static body weight; at 6 feet, Lilly finds packing pounds on and picking pounds up are closely connected, so he has worked up into his sport’s top weight class, Super Heavyweight.

“For me, I’ve yet to find the point where bigger isn’t better from a lifting standpoint,” Lilly said.

Better for lifting, yes. But pushing your body to unnatural extremes has its downsides.

“I never wake up pain-free,” Lilly said. “My lower back is constantly an issue. I have an ongoing hip problem. My left elbow hurts so bad I can’t even straighten it out. I’m probably going to tear my pec in a year or two.”

His sleep schedule is erratic: “I’m constantly exhausted. I was probably up seven times last night.”

Then there’s Lilly’s diet, which calls for 7,000-8,000 calories per day to keep his weight up. Some of his feasts sound like feats — he throttled The Thurmanator, Thurman Cafe’s 1.5-pound beast burger, and he recently slammed 100 pieces of all-you-can-eat sushi — but even at his size, finishing that much food is a grim chore. His grocery budget is about $125 per week, and he sometimes spends as much as $70 a day eating out. Savings, investment returns and freelance personal training fund his pursuit of power.

With so much discomfort, what drives him to press on? “Being the runt,” he said. “Being the little kid. Getting picked on.”

Lilly was an all-state soccer player in Berea, Kentucky. When he transferred schools for academic reasons and lost a season of eligibility, he took to pumping iron in a makeshift gym at a football coach’s farmhouse. Lilly tried bodybuilding but soon decided he wanted a sport in which his performance, not judges’ opinions, dictated the outcome.

After years of casual lifting, he began dabbling in strongman competitions in 2007. Eventually he discovered powerlifting, and by late 2009, he was so impressive that Louie Simmons invited him to train at the famed Westside Barbell in Columbus.

“I thought that was the paramount day of my life,” Lilly said.

He improved massively at Westside, but last March Lilly was dropped from the roster after suffering a hip injury. He called up world-record-holder and Westside defector Chuck Vogelpohl at Lexen Xtreme and resumed training.

Lilly will return to competition Saturday at the Xtreme Powerlifting Coalition’s International Open at Ultimate Sports Center. His final session of heavy training was last Wednesday evening.

After stopping by Raising Cane’s for pre-workout sustenance — he had already downed sushi and Bob Evans — he headed to Lexen, where he applied horse ointment to his skin and psyched himself up to the sounds of Gucci Mane and White Zombie. He tightly wrapped his black elastic wristbands and strapped on a red Inzer bench shirt, a sort of jersey-turned-corset that helps him get more leverage.

First he grunted his way through a 705-pound bench. After huffing around the room, he tackled a 795 as teammates cried “Belly up! Belly up!” Lifting partners laid wooden paddles of varied thickness (“two board,” “one board,” “half board”) across his chest, allowing him to skip the initial push off his chest and focus on perfecting the awkward, make-or-break middle part of the motion. After more stomping and exhausted leaning, Lilly struggled through an 805-pound bench.

His Ohio State baseball cap now soaked to a new shade of red, Lilly maxed out at 845 pounds with a two board. He’s never pushed that much weight without a board — his personal record is 810 — but with the two board he managed to less-than-gracefully force the bar back to its resting place, his limits officially tested.

After an hour of sitting, pacing and stretching his back on what looked like an oversized baker’s rolling pin, it was off to Chipotle with his teammates for a nightcap burrito bowl with double steak, then another sleepless night on what he hopes is the road to glory.